Field of the Invention
The subject matter of this patent application was developed without Federal or State funding. Although the inventor named herein is the beneficiary of support from various corporate organizations, and is employed by a University at which he works on subject matter including the development and characterization of materials formed by the direct growth of graphene on various substrates, no University time, compensation or apparatus was employed, involved or relied on in the development of the subject matter disclosed and claimed herein. Thus, this invention and the claims presented herein reflect work done by the inventor without funding or support on the development of field effect transistors formed by graphene deposition.
Background of the Technology
Graphene displays electronic properties, including high room temperature carrier mobilities, long carrier mean free paths,[1-3] polarizeability in proximity to a magnetic substrate[4] and long spin diffusion lengths[5] with exciting potential for charge or spin-based device applications. A critical step in practical device development, however, is the direct, controlled growth, by industrially feasible and scalable methods, of high quality single or few layer graphene films on dielectric substrates. Methods such as chemical or physical vapor deposition (CVD, PVD) or molecular beam epitaxy (MBE) are of interest, but must occur at growth temperatures allowing integration with Si CMOS or other device materials. Most reports, however, have involved graphene/substrate interfaces formed by one of two approaches: (a) physical transfer of graphene sheets—grown by CVD on metal substrates[6,7] or taken from HOPG;[1,2] or (b) the growth of graphene layers by high temperature evaporation of Si from SiC(0001).[8-10] The former method presents significant problems for practical device production, including formation of nanoscale interfacial electronic inhomogeneities.[11] The second method appears limited to SiC(0001) substrates. Recent reports of MBE graphene growth on SiC(0001)[12,13] are also limited to SiC substrates. The ability to grow single or few layer graphene on oxides or other dielectric substrates of choice would not only enhance graphene integration with Si CMOS, but also facilitate the development of novel multifunctional non-volatile devices[14,15] that exploit substrate functionality and graphene/substrate interactions.